a + b = 7 এবং ab = 12 হলে a - b = কত?
A
3
B
22
C
1
D
4
Correct Answer: 1
(a-b)2 = (a+b)2 - 4ab(a-b)2 = (7)2 -4×12(a-b)2 = 49-48=1so, a-b=1Ans : 1